While Cisco has dabbled in SDN technology for years, it lacked a coherent plan for how IT teams could embrace its vision for software-controlled infrastructure and services while preserving investments in the vast array of hardware already deployed.
That changed in November when the company announced its Application Centric Infrastructure (ACI), a grand blueprint that goes beyond low-level flow control and virtual network management to include enterprise-wide regulation and automation of application use, performance and security policies, orchestration of virtual network services, and management of physical and virtual network configuration.
This is achieved through a new Application Policy Infrastructure Controller (APIC), which incorporates a litany of supported APIs and protocols, including OpenFlow, OVSDB (Open vSwitch), onePK (Cisco’s management and automation API), NETCONF (network configuration), Cisco’s Application Virtual Switch, an evolutionary follow-up to the Nexus 1000V, and the recently announced OpFlex. Cisco also introduced a new line of switching hardware, the Nexus 9000, that is tightly integrated with the ACI and APIC control framework via a new generation of firmware.
But as Network Computing columnist Greg Ferro pointed out , ACI is a mouthful for existing Cisco customers to swallow.
“The ACI platform has many moving parts including software and hardware, and will take years to achieve momentum,” Ferro wrote in a blog post. “It took Cisco 90 minutes to explain the entire product and technical strategy to me. Customers are being asked to embrace and buy into Cisco’s very specific and very large network vision of the future.”
As if ACI/APIC weren’t enough, Cisco has also released the first commercial version of the OpenDaylight project’s controller. Called the Extensible Network Controller, it supports OpenFlow and onePK for southbound control over traffic and switch configuration, with new REST and Java northbound APIs for integration with other network services.
Cisco’s SDN strategy, based on an entirely new hardware and software architecture, has some legacy customers questioning the migration path. Indeed, the InformationWeek SDN survey found most IT organizations are loath to make wholesale architectural changes and unwilling to do a rip-and-replace upgrade to accommodate SDN. This is a problem for most every SDN vendor, not just Cisco -- particularly for those using physical-layer hardware and control protocols, such as OpenFlow, as opposed to virtual network overlays. Only 35% of survey respondents were very or completely willing to make significant network changes for SDN implementations.
Arista espouses programmable, automatable, virtual/cloud networks while eschewing the SDN label for any specific product. Instead, Arista has a broader strategy to incorporate cloud-based management and automation software into its non-blocking switching fabric, a.k.a. its Spline architecture.
The firm’s Software Defined Cloud Networking approach is built on four technology pillars: a standards-based network fabric using MLAG (L2) and ECMP (L3); cloud-based network control via services utilizing its extensible EOS platform; network-wide virtualization using any combination of its own EOS APIs, VXLAN tunnels, and Microsoft Open Management Infrastructure; and network applications and automation using its CloudVision software. Arista also works with network overlay vendors such as PLUMgrid to tighten integration between physical and virtual networks.
Hewlett-Packard is firmly committed to OpenFlow physical-layer SDN and had the broadest selection of compatible products in the Network Computing SDN Buyer’s Guide last year. It now supports OpenFlow in five switch product lines ranging from branch office edge devices to datacenter core chassis.
Controlling the hardware is HP’s Intelligent Management Center, which includes a virtual application networking SDN module that monitors and manages the three key layers of HP’s SDN architecture: infrastructure hardware; control plane and applications; and management of OpenFlow topology, controller, devices, and traffic. HP is also trying to foster an ecosystem for SDN applications by introducing an SDK and app store for its OpenFlow controller.